Elevator safety device.



W. H. GRAHAM, ELEVATOR SAFETY DEVICE.

APPLICATION FILED DEC. 29, 1911.

Patented May 28, 1912.

3 SHBETSSHEET 1.

INVENTOR a 44 [m ATTORNEYS W. H. GRAHAM.

ELEVATOR SAFETY DEVICE.

AEPLIOATION FILED DEC. 29, 1911.

1 ,O27,840. Patented May 28, 1912.

3 SHEETS-SHEET 2.

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V TOR ram/77 ATTORNEYS Patented May 28, 1912.

INVENTOR WITNESSES ATTORNEYS I WILLIAM H. GRAHAM, OF PITTSBURGH,PENNSYLVANIA.

ELEVATOR SAFETY DEVICE.

Specification of Letters Patent.

Patented May 28,1912.

Application filed December 29, 1911. Serial No. 668,542.

To all whom it may concern:

Be it known that I, WILLIAM H. GRAHAM, a citizen of the United States ofAmerica, residing at Pittsburgh, in the county of Allegheny and State ofPennsylvania, have in vented certain new and useful Improvements inElevator Safety Devices, of which the following is a specification,reference being had therein to the accompanying drawing.

This invention relates to a safety device for elevators, and the primaryobject of my invention is the provision of positive and reliable means,in a manner as will be hereinafter set forth in connection with cablehoisted elevators, for preventing a sudden descent of an elevator cageshould the hoisting cables thereof break.

Another object of this invention is to furnish an elevator cage withgripping shoes and the cage guides with stop blocks, said shoes and saidstop blocks being automatically actuated to retard and eventually stopthe sudden descent of an elevator cage.

A further object of this invention is to accomplish the above results bya mechanical construction that is durable, inexpensive to manufacture,and highly efiicient for the purposes for which it is intended.

With the above and other objects in view, the invention resides in thenovel construc tion, combination and arrangement of parts to behereinafter specifically described and then claimed.

Reference will now be had to the drawing wherein there are illustratedthe preferred embodiments of my invention, but it is to be understoodthat the structural elements are susceptible to such variations andmodifications as fall within the scope of the appended claim.

In the drawings like numerals denote corresponding parts throughout theseveral views, in which Figure 1 is a front elevation of a portion of anelevator shaft in accordance with this invention, Fig. 2 is a verticalsectional view of the same, Fig. 3 is an enlarged side elevation of anelevator cage in accordance with this invention, Fig. 4 is a frontelevation of the same, Fig. 5 is a detail perspec' tive viewillustrating the arrangement of the hoisting cable, Fig. 6 is anenlarged front elevation of a portion of the elevator shaft, partlybroken away and partly in section, illustrating one of the stop blocks,Fig. 7 is a cross sectional view of the same, illustrating one of thehoisting pulleys, Fig. 8 is a front elevation of a modified form ofgripping shoe, and Fig. 9 is a side elevation of the same, partly brokenaway and partly in section.

The reference numerals 1 denote vertical oppositely disposed guideshaving the con-' fronting faces thereof V-shaped, as at 2. The upperends of the guides 1 are connected by a transverse beam 3 having acentral oblong opening 4:.- Movably mounted within the opening 4: is ahousing 5 and journaled in said housing is a transverse pin 6 upon whichthere is mounted a grooved hoisting pulley 7. The housing 5 has lateralflanges 8 provided with openings 9 and extending through said openingsare guide pins 10 that are screwed or otherwise mounted in thetransverse beam 3. The guide pins 10 extend upwardly through sockets 11in the beam 3 and arranged within said sockets and encircling said pinare coiled compression springs 12. The tension of the springs 12 issuflicient to elevate the housing 5 when pressure is released upon thehoisting pulley .7.

To limit the movement of the housing 5, the beam 3 is provided with caps14. for the guide pins 10, said caps being bolted or otherwise secured,as at 15 to the beam and each cap has a recess 16 providing clearancefor the lateral flanges 8 of the housing 5.

Mounted upon the lateral flanges 8 of the housing 5 is an invertedU-shaped yoke 17. Pivotally connected to the yoke 17 by pins 18 are theinner ends of levers 19, said levers being fulcrumed by pins 20 inbearings 21, carried by the beam 3. Pivotally connected to the outerends of the levers 19 by pins 22 are the upper bifurcated ends ofsockets 23 on rods 2a, said rods extending through openings 25 providedtherefor in the beam 3 and downwardly at the sides of the guides 1. 7

Throughout the length of the guides 1 there are casings 26 through whichthe rods 24 extend. The casings 26 are carried by the guides, and withinsaid casings there are pivoted stop blocks 27 that are retained thereinby pins 28. The stop blocks 27 are pivotally connected by links 29 tobearings 30, carried by the rods 24. The stop blocks 27 are limited intheir movement by stop pieces 31 located within the casings 26. Theupper ends of the stop blocks 27 are notched, as at 32 for a purposethat will hereinafter appear.

The reference numeral 33 denotes a rectangular frame around which can bebuilt an elevator cage. This frame will be hereinafter referred to asthe elevator cage. Arranged upon the top of the cage 33 is a movable oryieldable housing 34 having lat eral flanges 35. The lateral flanges 35are provided with openings to receive side'pins 36, carried by the topof the cage. The guide pins 36 are provided with heads or caps 37, andencircling said guide pins, be tween the heads 37 and the flanges 35,are coiled springs 38, said springs retaining the lateral flanges 35normally in engagement with the top of the cage 33. Revolubly mountedwithin the movable housing 34 are grooved hoisting pulleys 39 and 40.Connected to the lateral flanges 35 of the housing 34. are yokes 41 andpivotally connected to said yokes by pins 42 are the inner ends oflevers 43, said levers being pivotally mounted or fulcrumed by pins 44in bearings 45, carried by the top of the cage 33.

Connected to the outer ends of the levers 43 are the upper ends ofstirrups 46, said stirrups extending downwardly at the sides of the cage33.

The bottom of the cage 33 is provided with a transverse steppeddepending beam 47, saidbeam having the front and rear sides thereofstepped, as at 48, 49 and 50. The ends of the beam 47 are inclined andprovided with dove-tailed inclined grooves 51 and movably arranged inthese grooves are gripping shoes 52 having flanges 53 engaging in thegrooves 51-. The outer sides of the shoes 52 have vertical grooves,V-shaped in cross section, and the walls of said grooves are providedwith teeth 54. The shape of the outer sides of the shoes 52 is such thatthe shoes can move into engagement with the sides or edges 2 of theguides 1, as will hereinafter appear. The stepped portion 48 is locatedupon the front side of the beam 47 and the ends of this stepped port-ionare adapted to be engaged by the stop blocks 27. The stepped portion ofthe beam 47 is provided with a vertical opening 55 to provide clearancefor one of the arms of the stirrup 46. The lower ends of the stirrups 46extend under the stepped portion 49 of the beam 47, and through thegripping shoes 52, whereby the gripping shoes 52 can be elevated by thestirrups 46.

The reference numeral 56 denotes a hoisting cable that passes downwardlyunder the pulley 39, upwardly over the pulley 7 and downwardly under thepulley 40, said cable having one end thereof anchored or secured to thebeam 3, as at 57 and the opposite end thereof connected to a suitablehoisting mechanism, (not shown). The weight of the elevator cage retainsthe housing 5 lowered and seated upon the beam 3, consequently the stopblocks 27 will be retained in a retracted position through the medium ofthe levers 19 and the rods 24. The weight of the elevator cage retainsthe housing 34 normally elevated and the stirrups 46 lowered, saidstirrups allowing the gripping blocks 52 to normally remain in a loweredposition out of engagement with the guides 1. Should the hoisting cable56 break, or either end thereof become detached, the sudden release ofthe elevator cage allows suflicient slack in the hoisting cable for thehousings 5 and 34 to shift. The former is elevated through the medium ofthe springs 12, the levers 19 and the rods 24 actuated, and the notchedupper ends of the stop blocks 27 shifted into the path of the off-setportion 48 of the beam 47, whereby the beam 47 Will strike the stopblocks 27 and be prevented from further descending. The movement of theelevator cage, before reaching the stop blocks 27 is retarded by thegripping shoes 52 engaging the guides 1. The gripping shoes 52 areelevated by the stirrups 46 and the levers 43, when the housing 34 isseated upon the cage 33. The sides of the elevator cage have slides 58and 59 to receive the guides 1.

In Figs. 8 and 9 of the drawings, there is illustrated amodification ofthe invention, wherein the ends of a beam 60 are cut away to receive theguides l, and the sides .of the guides are provided With longitudinalgrooves 61. The ends of the beam 60 have tapering grooves 62 forgripping shoes 63 that are elevated by rods 46 to engage in the grooves61 of the guides 1. In this man: ner the V-shaped edges of the guidesare not injured by the gripping shoes.

l/Vhat I claim is In a safety device for elevators, the combination withguides, a beam carried by the upper ends thereof, a cage slidablebetween said guides, a hoisting cable for moving said cage, stop blockscarried by said guides and adapted to be shifted into the path of saidcage, and gripping shoes carried by said cage and adapted to movesimultaneously with said stop blocks and engage said guides, of anormally seated movable housing carried by said beam, a pulley journaledin said housing, a normally unseated housing carried by said cage,pulleys journaled in said housing and together with the pulley of thefirst mentioned housing receiving In testimony whereof I affix mysignature said 1llloiisiting cable, and means for unseatin the presenceof tWo Witnesses.

ing t e rst mentioned housin and seating the second mentioned housin gWhen said WILLIAM GRAHAM a cable is released whereby said stop blocksWitnesses:

and said shoes Will be actuated to retard the MAX H. SROLOVITZ,

movement of said cage. CHRISTINA T. HOOD.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents.

Washington, D. G.

